Allanblackia is a plant belonging to genus Allanblakia of family Guttifera which widely grows in Africa from Sierra Leone to Zaire, Rwanda, and Tanzania, and the genus includes some species such as Stuhlmannii, Floribunda, Parviflora, and Klainei. Floribunda is a tree having a height of 25 m and a diameter of 0.8 m, and grows in dense forests of a high humidity on a coast line in Ivory Coast. A fruit of the tree is larger as compared with other fruits in forests right on the equator, and has a cannonball shape having a length of about 30 cm and a diameter of 10 cm. This fruit is longitudinally separated into five chambers, and seeds are regularly aligned in two rows in each chamber. About 40 to 100 seeds (nuts) are contained in a fruit. In any species, its seed (nut) contains 50% or more of a fat in content, and sometimes as much as 70% of a fat.
The allanblackia fat contains a high content (60 to 80% by weight) of SOS (2-oleoyl, 1,3-disaturated triglycerides), and the rest is mainly composed of SOO (1 (or 3)-saturated-2,3 (or 1) dioleoyl triglycerides), and the content of SSS (wholly saturated triglycerides) is extremely low. As applications of the allanblackia fat, inventions such as use as one component for production of a chocolate (Patent Document 1), and utilization for the purpose of improving quality of a hard butter (Patent Document 2) have been found out. However, no idea of fractionating the allanblackia fat to concentrate particular triglyceride components for use has been found out.
On the other hand, the present applicant has succeeded in utilizing a high oleic sunflower oil in production of a hard butter as in Patent Document 3. This production process is a process for producing a hard butter composition including selectively introducing a saturated fatty acid into 1,3 positions of a fat or oil containing a high oleic sunflower oil as a part or all of the raw material, and fractionating the fat or oil to obtain a fat or oil rich in SUS (2-unsaturated, 1,3-disaturated glycerides). This is a method of converting a fat or oil containing UUU (triunsaturated fatty acid triglycerides) as a main component into a fat or oil rich in SUS by selectively introducing a saturated fatty acid into 1,3 positions of a high oleic sunflower oil as a raw material using a lipase having 1,3-position-specificity. However, the reaction oil obtained by the above method has an insufficient SUS content as a hard butter in the fat or oil. And, this process for producing a hard butter includes obtaining a medium melting point fraction having an increased SUS content of at least 50% by weight by subjecting the reaction oil to further fractionation in order to make a hard butter of good quality. According to this process, a hard butter composition of high quality can be stably produced. However, since a large amount of a saturated fatty acid introduction source in a substrate for interesterification with a lipase is necessary and whereby a bulky reactor is required, and a facility for fractionation and concentration by solvent fractionation is necessary after the reaction, there is a problem that the facility cost relating to an interesterification reaction and fractionation is too high.
In addition, the present applicant has also disclosed a method of increasing the SUS content without concentrating by solvent fractionation etc., as in Patent Document 4. This method is to perform interesterification of a raw material fat or oil and a fatty acid or a fatty acid ester to be introduced into 1,3 positions, with a 1,3-specific lipase, by dividing the reaction into a multistage, and thereby phased increasing the SUS content to obtain a hard butter of good quality, in such a fat or oil processing aspect that stearic acid is introduced into 1,3 positions of a fat or oil fraction rich in POP (2-oleodipalmitin), or palmitic acid or stearic acid is introduced into 1,3 positions of a fat or oil fraction rich in triolein.
For example, by repeating an interesterification reaction of 50 parts by weight of raw material fat or oil and 50 parts by weight of fatty acid ester five times, a fat or oil very similar to a cacao butter is obtained without fractionation and concentration by a solvent. According to this method, there is an advantage that a hard butter of good quality is obtained only by interesterification with a lipase and that a fractionation step is not essential, but there is a problem that it is necessary to perform an interesterification reaction in multistage, and that a production yield of a hard butter from a lipase reaction facility is low. In order to solve this problem, Patent Document 4 discloses a method of reducing the number of interesterification reactions to two stages to slightly increase the SUS content, and obtaining a cacao butter substitute having the objective SUS content by solvent fractionation, but this is also a method with which there remains a problem that repetitive utilization of an interesterification reaction facility, and that a fractionation facility is necessary.
On the other hand, an oil from a new breeding sunflower subsequent to a high oleic sunflower oil has also been disclosed. For example, species such as high stearic acid species of Patent Document 5 and high-stearic and high-oleic species of Patent Document 6 have already been known. However, their applications are margarine, shortening, and confectionery, and no description of utilization in a hard butter can be found. In addition, there is also a trial of directly fractionating a high-stearic and high-oleic sunflower oil to obtain an SUS fraction. Patent Document 7 is a representative example thereof and discloses a fat or oil for a margarine consisting of a hard fraction of a high-stearic and high-oleic sunflower oil and a vegetable liquid oil at a weight ratio of 20:80 to 80:20. In the previous fat or oil for margarine and shortening, hydrogenated oils of animal or vegetable fats or oils have been widely used, but since these hydrogenated fats or oils contain a large amount of trans fatty acids, which are problem in the risk on health in recent years. So the trial is that a high-stearic and high-oleic sunflower oil is directly fractionated to obtain an SUS fraction, as one of hard fats or oils not containing trans fatty acids. However, in this method, the fractionation yield is low and, moreover, the SUS content of the hard fraction is extremely low.